Just to clarify: card readers accept all kinds of files. You can use your flash card to backup files. Your Book port can also act as a card reader if connected to your computer. It shows up as an extra drive in windows explorer. You can view/copy any file you want. The only limitation is, you can't actually read text files on the book port once you disconnect it unless they're filtered for the book port. But if you just want to backup/restore files on a card using your computer, you can use the book port to do that.